One key element is often the exploration of a new relationship dynamic. Since they are not a canon pairing, it's interesting to see how they interact. Another element can be the alteration of the existing story's setting to fit their relationship.
A fanfiction that stands out is 'Parallel Paths'. This story takes Bella Swan and David Mates on parallel but intertwined paths. It starts with them having their own separate lives but then circumstances bring them together in a very unexpected way. The author does a great job of building their relationship gradually. There are also elements of mystery and adventure in it which add to the overall appeal.
One key element is the unique relationship dynamics. Bella's relationships with Marcus and Alistair are different from the normal vampire - human relationships. It's often about exploring new kinds of love and loyalty.
One key element is the relationship between them. Whether it's a friendship or something more romantic, it's central to the story. For example, in many fanfictions, David 8's cold, logical nature contrasts with Bella's more emotional and impulsive side, creating an interesting dynamic.
One key element is the deep emotional connection. Since they are mates, there's this intense bond that is often explored. Another is the struggle against the norms of the vampire - human relationship in the 'Twilight' world.
One key element is the transformation of their relationship. In the original story, their relationship is complex, and in fanfiction, it often evolves in different directions. Another is the werewolf lore. Writers often expand on the werewolf aspects related to Jacob, which affects his relationship with Bella.
The character development of both Bella and Peter is crucial. Writers usually show how they change and grow because of their relationship. For instance, Bella might become more confident, and Peter might become more empathetic. Another element is the setting. It can range from a modern - day urban setting to a fantasy world, which greatly influences the story and how their relationship unfolds.
One key element is the development of their relationship. It usually starts from a somewhat tense or at least an uncertain beginning and then gradually evolves into a deep bond. For example, they might initially misunderstand each other due to their different backgrounds.
A key element is the unique bond between Bella and Felix. It's often a supernatural or fated connection that drives the story. For example, in many stories, their bond defies the normal rules of vampire - human relationships.
One key element is the re - imagining of their relationship. In fanfiction, their bond is often deepened and explored more fully. For example, their shared interests or how they communicate in a more open way.
A major element is the relationship between Bella and Diablo. It could be a relationship of enmity, where Bella is trying to stop Diablo's evil plans. Or it could be a more complex relationship where they have to work together for some reason. Also, the use of Diablo's lore, like the different types of demons and magic, is key in these fanfictions.